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CLEMASTINE FUMARATE
Overview
Active ingredients
Source: NDC Directory| Ingredient | Strength | RxCUI | Monograph |
|---|---|---|---|
| Clemastine Fumarate | .67 mg/5mL | 857430 | — |
Forms, strengths and routes
Source: NDC DirectoryRegulatory status
Source: Drugs@FDANDC Directory| Product | Trade name | Form | Strength | Ingredient | Status | TE | Flags |
|---|---|---|---|---|---|---|---|
| 074884-001 | CLEMASTINE FUMARATE | SYRUP | CLEMASTINE FUMARATE | Prescription | AA |
Therapeutic equivalence
Source: Orange BookWhat this rating means: Therapeutically equivalent — no known or suspected bioequivalence problems (conventional dosage forms)
Codes beginning with “A” indicate products the FDA considers therapeutically equivalent. Codes beginning with “B” indicate bioequivalence has not been established. See methodology.
Approval history
Source: Drugs@FDA| Type | No. | Action | Status | Date | Review |
|---|---|---|---|---|---|
| Supplement | 2 | Labeling | Approved | May 31, 2002 | — |
| Supplement | 1 | Manufacturing (CMC) | Approved | May 31, 2002 | — |
| Original application | 1 | Approved | December 17, 1997 | — |
Prescribing information
Source: openFDA Drug LabelingReproduced verbatim from the Structured Product Labeling submitted to the FDA (effective 20241125). This is the manufacturer's labelling text, not a summary and not advice.
Indications and Usage
openFDA Drug LabelingINDICATIONS AND USAGE Clemastine Fumarate Syrup is indicated for the relief of symptoms associated with allergic rhinitis such as sneezing, rhinorrhea, pruritus and lacrimation. Clemastine Fumarate Syrup is indicated for use in pediatric populations (age 6 years through 12) and adults (see DOSAGE AND ADMINISTRATION ). It should be noted that clemastine fumarate is indicated for the relief of mild uncomplicated allergic skin manifestations of urticaria and angioedema at the 2 mg dosage level only.
Dosage and Administration
openFDA Drug LabelingDOSAGE AND ADMINISTRATION DOSAGE SHOULD BE INDIVIDUALIZED ACCORDING TO THE NEEDS AND RESPONSE OF THE PATIENT. Pediatric: Children aged 6 to 12 years: For Symptoms Of Allergic Rhinitis -The starting dose is 1 teaspoonful (0.5 mg clemastine) twice daily. Since single doses of up to 2.25 mg clemastine were well tolerated by this age group, dosage may be increased as required, but not to exceed 6 teaspoonfuls daily (3 mg clemastine). For Urticaria and Angioedema -The starting dose is 2 teaspoonfuls (1 mg clemastine) twice daily, not to exceed 6 teaspoonfuls daily (3 mg clemastine). Adults and Children 12 years and Over: For Symptoms Of Allergic Rhinitis -The starting dose is 2 teaspoonfuls (1.0 mg clemastine) twice daily. Dosage may be increased as required, but not to exceed 12 teaspoonfuls daily (6 mg clemastine). For Urticaria and Angioedema -The starting dose is 4 teaspoonfuls (2 mg clemastine) twice daily, not to exceed 12 teaspoonfuls daily (6 mg clemastine).
Contraindications
openFDA Drug LabelingCONTRAINDICATIONS Antihistamines are contraindicated in patients hypersensitive to the drug or to other antihistamines of similar chemical structure (see PRECAUTIONS - Drug Interactions ). Antihistamines should not be used in newborn or premature Infants. Because of the higher risk of antihistamines for infants generally and for newborns and prematures in particular, antihistamine therapy is contraindicated in nursing mothers (See PRECAUTIONS - Nursing Mothers ).
Warnings
openFDA Drug LabelingWARNINGS Antihistamines should be used with considerable caution in patients with: narrow angle glaucoma, stenosing peptic ulcer, pyloroduodenal obstruction, symptomatic prostatic hypertrophy, and bladder neck obstruction. Use with CNS Depressants: Clemastine fumarate has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc.) Use in Activities Requiring Mental Alertness: Patients should be warned about engaging in activities requiring mental alertness such as driving a car or operating appliances, machinery, etc. Use in the Elderly (approximately 60 years or older): Antihistamines are more likely to cause dizziness, sedation, and hypotension in elderly patients.
Adverse Reactions
openFDA Drug LabelingADVERSE REACTIONS The most frequent adverse reactions are italicized: Nervous System Sedation , sleepiness , dizziness , disturbed coordination , fatigue, confusion, restlessness, excitation, nervousness, tremor, irritability, insomnia, euphoria, paresthesia, blurred vision, diplopia, vertigo, tinnitus, acute labyrinthitis, hysteria, neuritis, convulsions. Gastrointestinal System Epigastric distress , anorexia, nausea, vomiting, diarrhea, constipation. Respiratory System Thickening of bronchial secretions , tightness of chest and wheezing, nasal stuffiness. Cardiovascular System Hypotension, headache, palpitations, tachycardia, extrasystoles. Hematologic System Hemolytic anemia, thrombocytopenia, agranulocytosis. Genitourinary System Urinary frequency, difficult urination, urinary retention, early menses. General Urticaria, drug rash, anaphylactic shock, photosensitivity, excessive perspiration, chills, dryness of mouth, nose and throat. To report SUSPECTED ADVERSE REACTIONS, contact Allucent at 1-866-511-6754 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Drug Interactions
openFDA Drug LabelingDrug Interactions Additive CNS depression may occur when antihistamines are administered concomitantly with other CNS depressants including barbiturates, tranquilizers, and alcohol. Patients receiving antihistamines should be advised against the concurrent use of other CNS depressant drugs. Monoamine oxidase (MAO) inhibitors prolong and intensify the anticholinergic effects of antihistamines.
Description
openFDA Drug LabelingDESCRIPTION Each teaspoonful (5 mL) of Clemastine Fumarate Syrup for oral administration contains clemastine 0.5 mg (present as clemastine fumarate, USP 0.67 mg). Other ingredients: alcohol 5.5% v/v, wild cherry flavor, fumaric acid, methylparaben, propylene glycol, propylparaben, purified water, saccharin sodium, sodium hydroxide, and sorbitol solution. Clemastine fumarate belongs to the benzhydryl ether group of antihistaminic compounds. The chemical name is (+)-(2R)-2-[2-[[(R)-p-Chloro-α-methyl-α-phenylbenzyl]- oxy]ethyl]-1-methylpyrrolidine fumarate and has the following structural formula: C 21 H 26 CINO.C 4 H 4 O 4 M.W. 459.97 CAS Registration Number 145976-57-9 Clemastine fumarate occurs as a colorless to faintly yellow, practically odorless, crystalline powder. Clemastine Fumarate Syrup is a clear, colorless liquid with wild cherry flavor and has an approximate pH of 6.2. "Image Description"
Overdosage
openFDA Drug LabelingOVERDOSAGE Antihistamine overdosage reactions may vary from central nervous system depression to stimulation. In children, stimulation predominates initially in a syndrome which may include excitement, hallucinations, ataxia, incoordination, muscle twitching, athetosis, hyperthermia, cyanosis convulsions, tremors, and hyperreflexia followed by postictal depression and cardio respiratory arrest. Convulsions in children may be preceded by mild depression. Dry mouth, fixed dilated pupils, flushing of the face, and fever are common. In adults, CNS depression, ranging from drowsiness to coma, is more common. The convulsant dose of antihistamines lies near the lethal dose. Convulsions indicate a poor prognosis. In both children and adults, coma and cardiovascular collapse may occur. Deaths are reported especially in infants and children. There is no specific therapy for acute overdosage with antihistamines. The latent period from ingestion to appearance of toxic effects is characteristically short (1/2-2 hours). General symptomatic and supportive measures should be instituted promptly and maintained for as long as necessary. Since overdoses of other classes of drugs (i.e., tricyclic antidepressants) may also present anticholinergic symptomatology, appropriate toxicological analysis should be performed as soon as possible to identify the causative agent. In the conscious patient, vomiting should be induced even though it may have occurred spontaneously. If vomiting cannot be induced, gastric lavage is indicated. Adequate precautions must be taken to protect against aspiration, especially in infants and children. Charcoal slurry or other suitable agents should be instilled into the stomach after vomiting or lavage. Saline cathartics or milk of magnesia may be of additional benefit. In the unconscious patient, the airway should be secured with a cuffed endotracheal tube before attempting to evacuate the gastric contents. Intensive supportive and nursing care is indicated, as for any comatose patient. If breathing is significantly impaired, maintenance of an adequate airway and mechanical support of respiration is the most effective means of providing adequate oxygenation. Hypotension is an early sign of impending cardiovascular collapse and should be treated vigorously. Although general supportive measures are important, specific treatment with intravenous infusion of a vasopressor titrated to maintain adequate blood pressure may be necessary. Do not use with CNS stimulants. Convulsions should be controlled by careful administration of diazepam or a short-acting barbiturate, repeated as necessary. Physostigmine may also be considered for use in controlling centrally mediated convulsions. Ice packs and cooling sponge baths, not alcohol, can aid in reducing the fever commonly seen in children. A more detailed review of antihistamine toxicology and overdose management is available in Gosselin, R.E., et al., "Clinical Toxicology of Commercial Products."
How Supplied / Storage and Handling
openFDA Drug LabelingHOW SUPPLIED Clemastine Fumarate Syrup: clemastine 0.5 mg/5 mL (present as clemastine fumarate, USP 0.67 mg/5 mL). A clear, colorless liquid with wild cherry flavor, in 120 mL bottle. 120 mL bottle (NDC 62135-713-41) Store at 20° to 25°C (68° to 77°F); excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature]. Manufactured for: Chartwell RX, LLC. Congers, NY 10920 L71572 Rev. 07/2023
Adverse event reports
Source: openFDA FAERSAttributed to this product's most-reported active ingredient: CLEMASTINE FUMARATE. Combination products with more than six active ingredients are not attributed, because a report count summed across a long ingredient list measures the list, not the medicine.
Packaging and NDCs
Source: NDC Directory| Package NDC | Product NDC | Labeler | Description | Marketing start |
|---|---|---|---|---|
| 62135-713-41 | 62135-713 | Chartwell RX, LLC | 120 mL in 1 BOTTLE (62135-713-41) | July 7, 2023 |
| 64950-324-12 | 64950-324 | Genus Lifesciences | 120 mL in 1 BOTTLE (64950-324-12) | November 22, 2024 |
| 62135-713 | 62135-713 | Chartwell RX, LLC | — | December 17, 1997 |
| 64950-324 | 64950-324 | Genus Lifesciences | — | November 22, 2024 |
Sources for this page
| Dataset | Agency | Used for |
|---|---|---|
| NDC Directory | FDA | Identity, ingredients, strengths, forms, routes, labelers, packages |
| Drugs@FDA | FDA | Application, sponsor, submissions, review documents, marketing status |
| Orange Book | FDA | Therapeutic equivalence codes, reference drug flags, patents, exclusivity |
| Drug Labeling | FDA / NLM | Prescribing information reproduced above |
| FAERS | FDA | Adverse event report counts |
Generated September 25, 2026 · 10 sections on this page.